Search for: All records

ABSTRACT Snails belonging to the genusBiomphalariaserve as obligatory intermediate hosts for the trematodeSchistosoma mansoni, the causative agent for the most widespread form of schistosomiasis. The simpler nervous systems of gastropod molluscs, such asBiomphalaria, provide advantageous models for investigating neural responses to infection at the cellular and network levels. The present study examined neuropeptides related to cholecystokinin (CCK), a major multifunctional regulator of central nervous system (CNS) function in mammals. A neural transcriptome generated from the CNS ofBiomphalaria alexandrinaincluded a transcript encoding two CCK‐related peptides, designatedBalex‐CCK1 (pEGEWSYDY_(SO3H)GLGGGRF‐NH₂) andBalex‐CCK2 (NYGDY_(SO3H)GIGGGRF‐NH₂). Peptide expression was examined inBiomphalaria glabrataat the mRNA level using the hybridization chain reaction (HCR) protocol and at the protein level using an antibody againstBalex‐CCK1. Expression was detected in 60–70 neurons distributed throughout the CNS, as well as in profuse fiber systems connecting the ganglia and projecting to the periphery. CCK‐like immunoreactive (CCK_li) fibers were also observed on organs associated with the cardiorespiratory (nephridium, mantle, gill) and male reproductive systems. A comparison of mRNA and peptide localization suggested that CCK expression could be regulated at the level of translation. A potential role of these peptides in mediating responses to infection by larval schistosomes is discussed.